Question

我尝试使用调整大小的图像制作一个简单的GridView，因此我获得了极高的设备内存使用率（43.57 MB）我在这里做错了什么？

我的GridView片段：

public class GalleryFragment extends Fragment {
    private ArrayList<String> mPathList;
    private ImageView mImageView;
    private GalleryAdapter mAdapter;
    private GridView mGridView;

private static final  String TAG = "GalleryFragment";

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.gallery_layout, container, false);

    new AsyncGalleryLoader().doInBackground();

    mGridView = (GridView) view.findViewById(R.id.gridView);

    mAdapter = new GalleryAdapter(mPathList);

    mGridView.setAdapter(mAdapter);

    return view;
}

private class GalleryAdapter extends ArrayAdapter<String>{

    public GalleryAdapter(ArrayList<String> items) {
        super(getActivity(), 0, items);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null){
            convertView = getActivity().getLayoutInflater().inflate(R.layout.gallary_item, parent, false);
        }

        if (mPathList.size() > 0){
            String path = mPathList.get(position);
            mImageView = (ImageView) convertView.findViewById(R.id.gallary_item_imageView);

            BitmapDrawable bitmap = PictureUtils.getScaledDrawable(getActivity(), path);
            mImageView.setImageDrawable(bitmap);
        }
        return convertView;
    }
}

private class AsyncGalleryLoader extends AsyncTask<Void, Void, ArrayList<String>> {

    @Override
    protected ArrayList<String> doInBackground(Void... params) {
        List<PhotoData> datas = PhotoData.listAll(PhotoData.class);
        mPathList = new ArrayList<String>();

        for (int i = 1; i<datas.size(); i++){
            try{
                String path = datas.get(i).getPath();
                File file = new File(path);
                if (file.exists()){
                    mPathList.add(path);
                }else {
                    datas.get(i).delete();
                }
            }catch (Exception e){
                Log.d(TAG, "Error");
            }
        }
        return mPathList;
    }

    @Override
    protected void onPostExecute(ArrayList<String> strings) {
        super.onPostExecute(strings);
    }
}

}

我用来调整设备图像大小的类：

public class PictureUtils {

    public static BitmapDrawable getScaledDrawable(Activity activity, String path){
        Display display = activity.getWindowManager().getDefaultDisplay();
        float bestWidth = display.getWidth();
        float bestHeight = display.getHeight();

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        float srcWidth = options.outWidth;
        float srcHeight = options.outHeight;

        int inSampleSize = 1;
        if(srcHeight > bestHeight || srcWidth > bestWidth){
            if(srcWidth > srcHeight){
                inSampleSize = Math.round(srcHeight / bestHeight);
            }else {
                inSampleSize = Math.round(srcWidth / bestWidth);
            }
        }
        options = new BitmapFactory.Options();
        options.inSampleSize = inSampleSize;

        Bitmap bitmap = BitmapFactory.decodeFile(path, options);
        return new BitmapDrawable(activity.getResources(), bitmap);
    }

    public static void cleanImageView(ImageView view){
        if (!(view.getDrawable() instanceof BitmapDrawable))
            return;
        BitmapDrawable drawable = (BitmapDrawable) view.getDrawable();
        drawable.getBitmap().recycle();
        view.setImageDrawable(null);
    }
}

Answer 1

问题是您的getScaledDrawable()方法获取位图并将其缩放到设备屏幕的大小。据我所知，你真正需要的是只获取应该是网格视图中单个项目大小的缩略图。因此，只需重写它以获取网格项public static BitmapDrawable getScaledDrawable(Activity activity, String path, int bestWidth, int bestHeight)的大小。

网格视图中内存使用率极高

1 个答案: